1. Field of the Invention
The present disclosure relates to a method for producing a thin oxidized carbon film that is a thin carbon film having an oxidized portion composed of oxidized carbon. The present disclosure also relates to an element having a thin oxidized carbon film, and a method for producing the element.
2. Description of Related Art
Substances made of carbon (C) take a wide variety of forms including, as well as diamonds, sheets, nanotubes, horns, and balls such as C60 fullerene. Furthermore, the physical properties of such substances are more various than their forms. The rich variety of physical properties prompts energetic research and development for application of the substances. Thin carbon films are one of the substances made of carbon. Among them, a thin carbon film composed of one or several carbon atom layers in which carbon atoms are sp2-bonded is called graphene. Graphene is a substance the isolation of which was realized in 2004, and its singular physical properties as a two-dimensional semimetal have been discovered one after another (Science, vol. 306, pp. 666-669 (2004)). Graphene has a singular band structure in which two π bands having linear band dispersion intersect at the Fermi energy. For this reason, it is expected that the carrier (electrons and holes) mobility in graphene should be ten or more times the carrier mobility in silicon (Si). There is a possibility that a high-speed and low-consumption electronic device can be realized by use of graphene.
In the case where graphene is used in an electronic device (e.g., a field-effect device such as a transistor), the considerably high electrical conductivity of graphene may need to be reduced. JP 2009-182173 A and Science, vol. 319, pp. 1229-1232 (2008) disclose that when the width of graphene in a direction perpendicular to a travel direction of carriers is reduced to several nanometers to several tens of nanometers, one-dimensional quantum confinement effect is created in the section of graphene that has such a width as indicated above, and that this section of graphene can be used, by virtue of the effect, as a semiconductor having an energy gap in the range of about sub-eV to several eV.
JP 2009-182173 A and Science, vol. 306, pp. 666-669 (2004) disclose methods for patterning graphene into a fine pattern by electron beam lithography and by dry etching using oxygen plasma. Science, vol. 319, pp. 1229-1232 (2008) discloses a fine processing method for forming graphene into a ribbon shape using ultrasonic wave, and also discloses that the ribbon-shaped graphene exhibits semiconductor properties. Applied Physics Letters, vol. 94, 082107 (2009) discloses fine processing of graphene by anodic oxidation using a needle of an atomic force microscope (AFM).